With the rapid development of the mobile communication technology, and the increasingly higher demand of people for the high rate data service, High Rate Packet Data (HRPD) Access Network has been constantly evolving. In order to realize the Inter-operation with the Enhanced Universal Terrestrial Radio Access Network (E-UTRAN), the HRPD Access Network evolved into an Evolved HRPD (eHRPD) Access Network.
FIG. 1 is a schematic diagram of the network structure of the inter-operation between E-UTRAN and eHRPD in the prior art. As shown in FIG. 1, the eHRPD Access Network includes an evolved Access Terminal (eAT), an evolved Access Network (eAN), an evolved Packet Control Function (ePCF), a High Rate Packet Data Serving Gateway (HSGW), an Authentication Authorization Accounting of Access Network (AN-AAA), wherein the eAT is connected with the eAN via an air interface, the eAN is connected to the evolved Packet Control Function entity via A8 and A9 interfaces, to the Authentication Authorization Accounting entity via A12 interface, to 1× Base Station via A21 interface, to Mobile Handoff Center/Simulated Mobile Handoff Center via A21 interface and through inter-operation solution function entity, or directly connected to the Mobile Handoff Center/Simulated Mobile Handoff Center via A1/A1p interface; the evolved Packet Control Function entity is connected with the High Rate Packet Data Serving Gateway via A10 and A11 interfaces; different A interfaces for transforming different signaling/data are connected between an initial evolved Access Network and objective Access Network; and eAN is also connected with the Mobility Management Entity (MME) of the E-UTRAN via S101 interface.
In the inter-operation network between the E-UTRAN and the eHRPD, the eAT can be accessed to the eHRPD system via the E-UTRAN system. Particularly, the eAT keeps residing in the E-UTRAN system via the S101 interface between the initial eAN and the MME, and in the meantime can realize the handoff toward the active state of the eHRPD through three phases of Pre-registration, Handoff Preparation and Handoff Execution, wherein during the Pre-registration phase, the eAT establishes a eHRPD session and relevant IP context with the eAN via S101 interface; during Handoff Preparation phase, after the E-UTRAN system determines the time for the handoff, the eHRPD system allocates the wireless resources; and during Handoff Execution phase, the eAT is accessed to eHRPD system via HRPD wireless interface according to the allocated wireless resources. Therefore, the seamless handoff from the E-UTRAN system to the eHRPD system can be realized.
In the process of the handoff toward the active state of eHRPD, during Pre-registration phase, since the eAT is accessed to the eAN via S101 interface, the HRPD connection between the eAT and the eAN is named as Virtual Connection (VC). Correspondingly, for the Handoff Execution phase, when the eAT is accessed to the eAN via HRPD wireless interface, the HRPD connection between the eAT and the eAN is named as physical connection.
Compared with physical connection, the Virtual Connection has the difference lying in that the establishment of Virtual Connection cannot result in the updating of the binding of Proxy Mobile IP (PMIP) on the core network side. Particularly, when the HRPD connection between the eAT and the eAN is Virtual Connection, the PMIP binding still is kept between the Packet Data Network Gateway (P-GW) and the Serving Gateway (S-GW). At this moment, the HSGW of eHRPD is unnecessary to initiate a PMIP binding updating operation to the P-GW. When Pre-registration phase is completed, the eAT leaves from the E-UTRAN and takes handoff to the eHRPD, and after the eHRPD network is captured, in the case that the PMIP binding is not established between the HSGW and the P-GW, the HSGW needs to initiate the PMIP binding updating operation to establish the PMIP binding between the HSGW and the P-GW.
Since the Pre-registration operation of the eAT occurs at any time prior to the handoff from the E-UTRAN to the eHRPD, there is the scenario that the eAT or the eAN needs to initiate the virtual connection releasing. For instance, when the eAN receives the command from operation maintenance backstage, or in the case that the eAN after determines the Pre-registration of the eAT, backs to the E-UTRAN coverage area in which the Pre-registration is not necessary and resides for an enough long time period and so on, it is unnecessary for the HSGW to initiate PMIP binding updating. However, in the prior art, there is no corresponding solutions for how to realize the virtual connection releasing and how to enable the HSGW not to initiate the PMIP binding updating under virtual connection.